Crab, I am not au fait with Bristow's ConOps, hence I said I was guessing at the "out of duty" time. It was a long old haul for Caernarfon. Likewise I have no insight into contractural matters so cannot answer your question on penalties etc.. (Maybe JIMF has the answer as he seems to have an inside line on these things)
Your point on East Coast SAR cover is however, most valid.